Closed source software can indeed raise concerns, particularly regarding the potential for malicious actors to distribute malware as executable files. This concern is valid because without the source code, users cannot verify the integrity and safety of the software. The transition to a proprietary license might be a response to such concerns, aiming to protect the software's integrity and prevent misuse. However, the decision to switch licenses often involves complex considerations that go beyond just security. Factors such as business strategy, funding, and the desire to control the development direction of the software can also play significant roles. Understanding the specific reasons behind the switch can provide valuable insights into the developers' priorities and the environment in which they operate. It's important to recognize that the choice of license is a multifaceted decision that balances various interests and needs.